The fluctuations of the mind are always known by its lord, the puruṣa, due to its immutability.

Here we arrive at the heart of yogic metaphysics. The vṛttis, mental modifications, are always known (sadā jñātāḥ) by puruṣa, the witnessing consciousness.

Puruṣa is prabhu, the lord or owner of the mind. But its lordship is not active but testimonial: it observes without participating, knows without modifying.

Apariṇāmitva is the key: puruṣa does not change. Unlike the mind, which constantly transforms, pure consciousness remains identical to itself. That’s why it can know all change: it is the immobile background against which movement is perceived.

If the knower changed with each knowledge, there would be no continuity of experience. But there is a constant witness observing all mental states, from deep sleep to most active waking.

Recognizing this immutable witness is Yoga’s goal: we are that which observes, not the observed.